Liposomes for effective drug delivery to the ocular posterior chamber

Pranoprofen Nanoparticles With Poly(L-Lactide)-b-Poly(Ethylene Glycol)-b-Poly(L-Lactide) as the Matrix Toward Improving Ocular Anti-inflammation

Nanotechnology using biodegradable polymer carriers with good biocompatibility and bioabsorbability has been studied and applied extensively in drug delivery systems and biomedical engineering. In this work, the triblocked oligomer poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLEL) with the molecular weight of 2.08 KDa was first synthesized. Its chemistry was characterized by hydrogen nuclear magnetic resonance (1H-NMR) spectrum and Fourier transform infrared (FTIR) spectroscopy. Subsequently, the nanoparticles (NPs) of PLEL and pranoprofen (PF)-loaded PLEL were prepared with the average particle size of (151.7 ± 5.87) nm using the method of emulsion solvent evaporation. The formula and drug releasing profile were characterized by a transmission electron microscope (TEM), dynamic light scattering (DLS), and ultraviolet spectrophotometer (US). In vitro cytotoxicity assays and in vivo ophthalmic tests were performed to measure the safety and efficacy of the formulations. The results showed that PF NPs relieved the cytotoxicity of pure PF and eliminated ophthalmic irritation. The drug encapsulated in the nanoparticles displayed long-lasting release and good anti-inflammation efficiency in animal eyes. Therefore, we concluded that the present formula (PF NPs) could provide sustained drug release with good treatment effect on eye inflammation, and is promising for its use in ophthalmology in the future.

Drug discovery and formulation development for acute pancreatitis

Acute pancreatitis is a sudden inflammation and only last for a short time, but might lead to a life-threatening emergency. Traditional drug therapy is an essential supportive method for acute pancreatitis treatment, yet, failed to achieve satisfactory therapeutic outcomes. To date, it is still challenging to develop therapeutic medicine to redress the intricate microenvironment promptly in the inflamed pancreas, and more importantly, avoid multi-organ failure. The understanding of the acute pancreatitis, including the causes, mechanism, and severity judgment, could help the scientists bring up more effective intervention and treatment strategies. New formulation approaches have been investigated to precisely deliver therapeutics to inflammatory lesions in the pancreas, and some even could directly attenuate the pancreatic damages. In this review, we will briefly introduce the involved pathogenesis and underlying mechanisms of acute pancreatitis, as well as the traditional Chinese medicine and the new drug option. Most of all, we will summarize the drug delivery strategies to reduce inflammation and potentially prevent the further development of pancreatitis, with an emphasis on the bifunctional nanoparticles that act as both drug delivery carriers and therapeutics.

Are Poly(amidoamine) Dendrimers Safe for Ocular Applications? Toxicological Evaluation in Ocular Cells and Tissues

Purpose: The human eye is a sophisticated and sensitive sensory organ. Because of the existence of the blood-ocular barrier and corneal-scleral barrier, safe and efficient ocular drug delivery system is highly desired; yet, it remains an unsolved issue. Due to the unique structure and drug loading property, Poly(amidoamine) (PAMAM) has received much attention in the ocular drug delivery investigation. Herein, we evaluated the ocular cytotoxicity and biosafety of PAMAM dendrimers. Methods: The ocular cytotoxicity and biosafety of PAMAM dendrimers were evaluated by conducting in vitro and in vivo experiments on ocular systems. The in vitro effect of PAMAM dendrimer of different generations (G4.0, G5.0, and G6.0) and concentrations on ocular cell metabolism, apoptosis, and oxidative damage were quantitatively assessed. In vivo biosafety of PAMAM dendrimers were further investigated on intraocular tissue by ocular irritation and intravitreal injection approaches. Results: It is found that that the cytotoxicity of PAMAM was time and generation dependent. PAMAM at a concentration below 50 μg/mL had minimal impact on the ocular tissue, whereas it caused apparent damage when above 50 μg/mL in the investigated situation. Further, our in vivo results showed that higher concentration of dendrimer (100 μg/mL) was associated with functional impairment demonstrated via optical coherence tomography and electroretinogram, although macroscopic structural changes were absent in fundus and histopathological studies. Overall, a higher concentration of PAMAM, such as above 50 μg/mL, may cause ocular functional damage. Conclusion: The PAMAM at the concentrations lower than 50 μg/mL showed good biocompatibility and biosafety in human ocular cells and tissues.

Nanoformulations for Ocular Delivery of Drugs - A Patent Perspective

Efficient delivery of ocular therapeutics with improved efficacy, enhanced bioavailability, and acceptable patient compliance presents unique challenges. This can be attributed to the presence of protective mechanisms, physicobiological barriers, and structural obstacles in the eye. Nanotherapeutic interventions have been explored extensively over the past few years to overcome these limitations. The present review focusses on the nanoformulations developed for the diagnosis and treatment of various ocular diseases besides providing an in-depth insight into the patents reported for the same.

Therapies Based on Nanoparticles for Eye Drug Delivery

Eye drug delivery, particularly to the retina, is a technical hurdle that needs to be solved and represents an ongoing current important medical field. Posterior segment eye diseases are a major cause of visual impairment worldwide. Age-related macular degeneration, glaucoma, and diabetic retinopathy are the major causes of blindness. To achieve efficient drug delivery and drug retention time in the posterior segment of the eye, novel delivery systems based on nanoparticles have been developed in the last few years. Nowadays, liposomes represent the most utilized nanoparticles for eye drug delivery and, recently, a broad spectrum of diverse nanoparticles continue to emerge with special characteristics representing ideal candidates for eye drug delivery.

Retinal photoreceptors targeting SA-g-AA coated multilamellar liposomes carrier system for cytotoxicity and cellular uptake evaluation

Here, the retinal targeting SA-g-AA coated multilamellar liposomes carrier synthesized to deliver the bioactive agents into the retinal region of the eye. The multilayered targeting macromolecules of liposomes prepared using a layer-by-layer assembly. The curcumin (CUR) and Rhodamine B (RhB) dyes loaded in a multilamellar vesicle (MLV) were synthesised by the lipid film hydration method. The sodium alginate grafted acrylic acid (SA-g-AA) conjugated with riboflavin (RB) was coated over MLV by O/W emulsion method followed by ionotropic gelation. FT-IR and ¹H NMR spectroscopy techniques used to analyse the structural features of the MLV-SA-g-AA-RB. The results of DLS and TEM revealed that the carrier could be of uniform spheres, with a low polydispersity index, and outstanding performance in phrases of dye encapsulation and extended-release ability. An MTT assay investigated cell viability against Fibroblast WS1, and human embryonic stem cells-derived retinal pigment epithelial cells (hESC-RPE) implied that the carrier is of excellent biocompatibility. Retina targeting nature of the system confirmed via cellular uptake results revealed that the increases the dye concentration in the cells. Overall, the outcomes suggested that carriers could lead to the improvement of a feasible two photoreceptors targeting drug carriers, and it has the potential to deliver the multidrug in the retinal region of the eye.

Therapies Based on Nanoparticles for Eye Drug Delivery

Eye drug delivery, particularly to the retina, is a technical hurdle that needs to be solved and represents an ongoing current important medical field. Posterior segment eye diseases are a major cause of visual impairment worldwide. Age-related macular degeneration, glaucoma, and diabetic retinopathy are the major causes of blindness. To achieve efficient drug delivery and drug retention time in the posterior segment of the eye, novel delivery systems based on nanoparticles have been developed in the last few years. Nowadays, liposomes represent the most utilized nanoparticles for eye drug delivery and, recently, a broad spectrum of diverse nanoparticles continue to emerge with special characteristics representing ideal candidates for eye drug delivery.

Trimethyl chitosan nanoparticles for ocular baicalein delivery: Preparation, optimization, in vitro evaluation, in vivo pharmacokinetic study and molecular dynamics simulation

To improve ocular bioavailability of baicalein (BAI), trimethyl chitosan coated lipid nanoparticles of baicalein (TMC-BAI-LNPs) were prepared, optimized and characterized. The properties of TMC-BAI-LNPs such as morphology, particle size, zeta potential and fourier transform infrared spectroscopy were investigated. Additionally, molecular dynamics simulation was applied as a new method to evaluate drug-biological membrane interactions. Transmission electron microscopy showed that the LNPs were approximately spherical in shape with a smooth surface. TMC-BAI-LNPs had a particle size of 162.8 nm, a positive surface charge with a zeta potential of 26.6 mV. The entrapment efficiency and drug loading values of BAI in the formulation were 90.65% and 2.04%, respectively. Moreover, in vitro drug release revealed that TMC-BAI-LNPs had a sustained release effect. In vivo studies indicated TMC-BAI-LNPs had no ocular irritation and the AUC of TMC-BAI-LNPs was 3.17-fold than that of the control (p < 0.01). Molecular dynamics simulation data showed that BAI had a poor membrane permeability, which limited the ocular bioavailability. The results indicated that TMC-BAI-LNPs might open up a new avenue for ocular administration. Furthermore, molecular dynamics simulation could predict permeability of drugs.

Noble Metals and Soft Bio-Inspired Nanoparticles in Retinal Diseases Treatment: A Perspective

We are witnessing an exponential increase in the use of different nanomaterials in a plethora of biomedical fields. We are all aware of how nanoparticles (NPs) have influenced and revolutionized the way we supply drugs or how to use them as therapeutic agents thanks to their tunable physico-chemical properties. However, there is still a niche of applications where NP have not yet been widely explored. This is the field of ocular delivery and NP-based therapy, which characterizes the topic of the current review. In particular, many efforts are being made to develop nanosystems capable of reaching deeper sections of the eye such as the retina. Particular attention will be given here to noble metal (gold and silver), and to polymeric nanoparticles, systems consisting of lipid bilayers such as liposomes or vesicles based on nonionic surfactant. We will report here the most relevant literature on the use of different types of NPs for an efficient delivery of drugs and bio-macromolecules to the eyes or as active therapeutic tools.

Nanomedicine Fight against Antibacterial Resistance: An Overview of the Recent Pharmaceutical Innovations

Based on the recent reports of World Health Organization, increased antibiotic resistance prevalence among bacteria represents the greatest challenge to human health. In addition, the poor solubility, stability, and side effects that lead to inefficiency of the current antibacterial therapy prompted the researchers to explore new innovative strategies to overcome such resilient microbes. Hence, novel antibiotic delivery systems are in high demand. Nanotechnology has attracted considerable interest due to their favored physicochemical properties, drug targeting efficiency, enhanced uptake, and biodistribution. The present review focuses on the recent applications of organic (liposomes, lipid-based nanoparticles, polymeric micelles, and polymeric nanoparticles), and inorganic (silver, silica, magnetic, zinc oxide (ZnO), cobalt, selenium, and cadmium) nanosystems in the domain of antibacterial delivery. We provide a concise description of the characteristics of each system that render it suitable as an antibacterial delivery agent. We also highlight the recent promising innovations used to overcome antibacterial resistance, including the use of lipid polymer nanoparticles, nonlamellar liquid crystalline nanoparticles, anti-microbial oligonucleotides, smart responsive materials, cationic peptides, and natural compounds. We further discuss the applications of antimicrobial photodynamic therapy, combination drug therapy, nano antibiotic strategy, and phage therapy, and their impact on evading antibacterial resistance. Finally, we report on the formulations that made their way towards clinical application.